Preparing the surfaces of grinding mill rolls



Au 15, 1950 F. TANNER v 2,518,836

PREPARING THE SURFACES 0F GRINDING MILL ROLLS Filed Aug. 20. 1948 23 22 g) 24 4 2 24 2 2 I If 5 I? 74- 9 H63 EAlElm-m llWt'A/TOR:

Patented Aug. 15, 1950 amass i warm st. eaten, sweetie-fie, as'sigfioi' as .Gbbriider Buhler, Uzwil, Switzerland 7 iipii'liatiiiii ire-ghetto, 1918, seriai asset" In Switzerland August 28, r943 the coarser and harder tnegieerie are.

My present intention relates to a method of and an arrangement for preparing the operative surfaces of giindirig-fiiill rolls with a view of improving-the efiiciency of grinding. .--In accord with my present'invention, the break-in orruirin time of :the rolls, as required up to the present, is eliminated, and the grinding-mill rolls receive such preliminary treatment as to produce-at ease, d'n'beingincorporatdih the mills 'a maxiefiici'ency'of grinding.

According to the method set out hereinafter, the rolls intended for co-operation are rotated in a sense opposite to each other, and a grinding-compound which is harder than the rollsurfaces, is fed into the crushing-gap.

Suitably at least one of the co-operating rolls is axially reciprocated during such rotation.

The arrangement according to my present invention comprises means for feeding the grinding-compound into the crushing-gap of the oppositely rotating rolls.

One form of an arrangement for carrying out the method of my present invention, is shown, by way of example, in the accompanying drawing, in which:

Fig. 1 shows a front view,

Fig. 2 a plan view,

Fig. 3 an end view, partly in section, and

Figs. 4-43 show details, partly in section.

The arrangement shown comprises a pedestal l, a frame 2 rigidly secured to the latter and having cheeks 3 on which the bed plates 4, 4 are displaceably mounted. Bearings 5, 5' for the axles 6, 6 of the rolls 1, 8 to be prepared, are adjustable along the said bed plates. The two rolls are driven in opposite sense by means of the belt 9, pulley l and gear wheels ll, l2. A grinding-compound harder than the rollsurfaces is fed into the crushing-gap l3 of the two rolls 1, 8. A dispensing-trough i is secured to a cantilever-structure l4 and serves for uniformly feeding the said compound over the entire roll-length. The said trough I5 is provided with outlets l6, and is filled with the grindingcompound, e. g. oil and quartz, which flows slowly and uniformly into the gap l3. The grindingcompound dropping from the rolls is caught in a tray l1. By grinding the said compound, the surface of the two rolls 1, 8 is roughened, and

:4 (jiaims. (01551 28 9!) the degree of such roughening and the efficiency of getiid g am se theretrem: ed withth or the the For the purpose (if the re11pressarea 0 baii' in s -5' of the ran 8 are adjustable es'sed, as desires, by t e spindles 1 8,; 141' anenanewheeis 9, i e". said spines set time the bearings s' and press marsh a the ren The 2 i.

are dispps d rn s l seeeree retire be i aslot 2'3. A pointer 24 (Til? 4) projects meag e th'e latter and emanates on a scene 25 the path covered by the spring or the spring-pressure so as to permit to set and read the desired rollpressure.

In order to avoid the occurrence of corrugations, during such preliminary grinding, one of the said rolls, e. g. 8, is axially reciprocated during rotation. To such end, discs 26, 26' are mounted on the two end-portions of the shaft 6', the adjacent end faces 21, 2'! of which are askew to the axis of the shaft 6, but parallel to each other. The skew face 21 of the disc 26 co-acts with a roller '28 which is rigidly adjustable with respect to the bearing-frame of the two rolls (Fig. 5), while in Fig. 6 the skew face 21' of the disc 26 co-acts with a roller 28' which is loaded by a spring 29 located in a threaded sleeve 30 also containing a plate 3| engaged by spring 29, said plate being adjustable in the sleeve by screw 32. The roller 28' is rotatably mounted at the outer end of plunger 33 which extends into sleeve 39 and engages spring 29. Through the co-operation of the discs 26, 26' with the rollers 28, 28 the roll 8 on rotation is axially reciprocated with respect to the roll I.

What I claim as new and desire to secure by Letters Patent is:

1. An arrangement for preparing or roughening the operative surfaces of two trued or newlymanufactured grinding-mill rolls with a view of improving their efficiency of grinding and avoiding the time otherwise required for breaking in the said rolls during actual operation, comprising a frame, a pair of bed plates slidably mounted on the latter, two pairs of bearing blocks which support the rolls and are slidably mounted on said plates for manually adjusting the contact pressure between said rolls, driving means for rotating the said rolls in opposite sense and means for imparting to one of said rolls an axially reciproeating movement during revolution, a quantity of 3 grinding compound disposed in a dispensing trough fixed to one of said plates and adapted to feed the said compound between the two rolls during revolution thereof.

2. An arrangement set out in claim 1, in which the rolls are provided with axle pins, the said means forimparting a reciprocating movement to one of said rolls comprising a disc keyed to each end-portion of the roll axle-pins, each disc having a face extending askew of its axle-pin and the skew faces of the two discs facing and being parallel to each other, a spindle engaged in and spective roll, a threaded sleeve engaged in and lockable to the other bearing block, a plunger disposed in said sleeve, a spring accommodated in said sleeve and abutting at oneend against a a spring plate and abutting at the other end against said plunger, a roller pivoted to said plunger and engaging the respective said skew face each so as to impart a spring-loaded reciprocating move--. ment to the respective roll on rotation thereof.

3. An arrangement set out in claim 1, in which each of the two contact-pressure adjusting means comprises a screw spindle having at one end a hand wheel keyed thereto and being threadedly engaged in its respective bed plate, a plate pinned to the other end of said spindle, a spring abutting at one end against said spindle plate and at the other end against the respective bearing block, a, housing fixed to the latter for accommodating the said plate and guiding the said spring, a manually operable locking nut engaging said spindle for locating the latter relative to said bed plate, and means for indicating the degree of com- 4 pression of the spring to permit the application of the same degree of compression to the springs at both ends of the respective roll.

4. An arrangement set out in claim 1, in which each of the two contact-pressure adjusting means comprises a screw spindle having at one end a handwheel keyed thereto and being threadedly engaged in its respective bed plate, a plate pinned to the other end of said spindle, a spring abutting at one end against said spindle plate and at the other end against the respective bearing block, a

' housing fixed to the latter for accommodating the lockable to one of the bearing blocks of the resaid plate and guiding the said spring, a manually operable locking nut engaging said spindle for locating the latter relative to said bed plate, said housing having a slot therein, and means for in- Till REFERENCES orrnn The following references are of record in the file of this patent:

UNITED STATES PATENTS Date Number Name 439,819 Howieson Nov. 4, 1890' 511,493 Banfield Dec. 26, 1893 

